asparagus bean vs snake bean

asparagus bean

noun
  • An east Asian type of bean with long, edible pods, the yardlong bean (Vigna unguiculata subsp. sesquipedalis). 

snake bean

noun
  • Vigna unguiculata subsp. sesquipedalis, a widely cultivated edible legume. 

  • Bobgunnia madagascariensis, a poisonous legume found in Africa. 

How often have the words asparagus bean and snake bean occurred in a corpus of books? (source: Google Ngram Viewer )